<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport"
          content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Title</title>
    <style>
        #watersheet{
            width: 50vw;
            height: 50vh;
            margin: auto;
            background-color: bisque;
        }
        #circle1{
            width: 300px;
            height: 300px;
            background-color: orange;
            margin: auto;
        }
        #circle2{
            width: 200px;
            height: 200px;
            background-color: palevioletred;
            margin: auto;
        }
        #target{
            width: 100px;
            height: 100px;
            background-color: lightgreen;
            margin: auto;
        }
    </style>
</head>
<body>
    <!--<div id="watersheet">
        <div id="circle1">
            <div id="circle2">
                <div id="target"></div>
            </div>
        </div>
    </div>-->
    <ul>
        <li>000000001</li>
        <li>000000002</li>
        <li>000000003</li>
        <li>000000004</li>
        <li>000000005</li>
        <li>000000006</li>
        <li>000000007</li>
        <li>000000008</li>
        <li>000000009</li>
        <li>000000010</li>
    </ul>
</body>
<script>
    function getEle(selector) {
        return document.querySelector(selector);
    }
    /*var waterSheet = getEle('#watersheet');
    var circle1 = getEle('#circle1');
    var circle2 = getEle('#circle2');
    var target = getEle('#target');
    waterSheet.onclick = function () {
        alert('watersheet');
    };
    circle1.onclick = function () {
        alert('circle1');
    };
    circle2.onclick = function () {
        alert('circle2');
    };
    target.onclick = function (e) {
        // e.cancelBubble = true;
        e.stopPropagation();
        alert('target');
    }*/
    var ul = document.getElementsByTagName('ul')[0];
    ul.onclick = function (event) {
        var e = event || window.event;
        var target = e.target || e.srcElement;
        if(e.altKey){
            target.style.background = 'red';
        }
        if(e.ctrlKey){
            console.log(target.innerHTML);
        }
    }
</script>
</html>